Training locomotion as early as possible is crucial for infants at risk for developing locomotor delays. Upright locomotion is difficult to exercise in these infants, especially from birth, as their body tone is low. Crawling is a better candidate because it not only eliminates the upright postural problem, but, also, exercises the arms to move in coordination with the legs, with arm movement being an important factor in mature bipedal locomotion. Moreover, crawling naturally exists at birth and as such is an excellent candidate for early training of locomotion. Training crawling on a mattress at birth, especially in infants with low body tone, has nevertheless to overcome one obstacle: supporting the weight of the head and the chest of the infant away from the surface in order not to block the infant's forward propulsion and to allow the arms to move. Pediatricians and kinesitherapists usually try to overcome this problem of helping infants to crawl by manually raising the infant's head and trunk off the floor and pulling them forward. This practice requires very specific skills that all pediatricians do not have, and influences the infant's movements depending on the manner in which the pediatrician supports the infant.
Devices for assisting infant crawling are already known, but are designed for infants of at least a few months of age. For example, document WO2011/146795 discloses a device facilitating crawling of infants who are at least 4 months of age and unable to propel themselves. The device is comprised of a motorized horizontal wheeled platform, on which the infant is placed in a horizontal prone position, that senses the infant's intent to move their legs and arms and engages movements of the wheels depending on the infant's intent, regardless of whether the infant's movements are effective or not. The device is not designed to enable the infant to move by his own strength as the strength of the arm and leg muscles needed to move the device is minimal. Therefore, it does not push the infant to express his maximal crawling muscle activity.